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Chemistry MCQ thread...
- Thread starter Zishi
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At a total pressure of 1.0 atm, dinitrogen tetraoxide is 50 % dissociated at a temperature of 60 C,
according to the following equation.
N2O4--> 2NO2
What is the value of the equilibrium constant, Kp, for this reaction at 60 C?
A 1/3 atm B 2/3 atm C 4/3 atm D 2 atm
how to solve this question ? :%)
according to the following equation.
N2O4--> 2NO2
What is the value of the equilibrium constant, Kp, for this reaction at 60 C?
A 1/3 atm B 2/3 atm C 4/3 atm D 2 atm
how to solve this question ? :%)
1 mol of sodium bromate reacts with 3 mol of hydroxylamine according to the data given..
the equation shows that bromate takes 6 mol of electrons to reduce itself so these electrons come from hydroxyl amine....3 mol of hydroxylamine giv 6 mol of electron so 1 mol will give 2 mol of electrons....
In giving 2 mols of electron...the oxidation number of nitrogen must increase by 2....
in hydroxyl amine the oxid number of nitrogen is -1 so by giving 2 mol of electrons the oxid number increases by 2
The new oxid number shld be +1...Only option C N2O shows this so C i corrct
the equation shows that bromate takes 6 mol of electrons to reduce itself so these electrons come from hydroxyl amine....3 mol of hydroxylamine giv 6 mol of electron so 1 mol will give 2 mol of electrons....
In giving 2 mols of electron...the oxidation number of nitrogen must increase by 2....
in hydroxyl amine the oxid number of nitrogen is -1 so by giving 2 mol of electrons the oxid number increases by 2
The new oxid number shld be +1...Only option C N2O shows this so C i corrct
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xHazeMx said:
Its C rite???
Hateexams93 said:
I was also goin to ask the same Q!!!
- Messages
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hassam said:
Okay, so it goes like this:
Changing the volumes and concentrations gives us moles of Nitrogen compound and bromine one:
NaBrO3 : Nh2OH
4x10^-4 : 1.2x10^-3
1 : x
x= 3
As one bromine atom gains 6 electrons. So each of Nitrogen atoms will loose 2 electrons.
In Nh2OH its oxidation state is -1, so by gaining two electrons its oxidation stat changes to +1. And Only N2O has oxidation state of nitrogen as +1.
xHazeMx said:
2 and 3.
Hateexams93 said:
Consider moles of N2O4 as 1 and that of NO2 as zero.
50% of N2O4 dissociates means that 1 moles of NO2 is formed. So total number of moles = 1.5
PArtial pressure of N2O4 = 0.5/1.5 = 1/3
Partial pressure of NO2= 1/1.5 = 2/3
So Kp = (2/3)^2 divided by (1/3). So 4/3 is the answer.
- Messages
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Its Q related to salt analysis.....
when AgNO3 is added to a solution containing halide ion there is always a precipitate!!!
On adding aq. NH3 the precipitate in solution containing Chloride ion, dissolves!!!
In bromide case, it is partially soluble!!
And in iodide, its insoluble so C is the rite ans!!!
when AgNO3 is added to a solution containing halide ion there is always a precipitate!!!
On adding aq. NH3 the precipitate in solution containing Chloride ion, dissolves!!!
In bromide case, it is partially soluble!!
And in iodide, its insoluble so C is the rite ans!!!
- Messages
- 118
- Reaction score
- 2
- Points
- 28
farrukh said:
I also thought the same but wasn't sure!!!
Someone pls answer...
Q. HCN adds to ketones...the table shows the relative rates of reactions under diff conditions
CONDITION ---------- RELATIVE RATE
aqueous solution --------- slow
acidified solution -------- virtually zero
alkaline solution --------- very rapid
Which is likely to be involved in the rate determining step of the reaction...
A. Cyanide ion
B. Hydroxide ion
C. H+ ion
D. HCN
E. H2O
Q. HCN adds to ketones...the table shows the relative rates of reactions under diff conditions
CONDITION ---------- RELATIVE RATE
aqueous solution --------- slow
acidified solution -------- virtually zero
alkaline solution --------- very rapid
Which is likely to be involved in the rate determining step of the reaction...
A. Cyanide ion
B. Hydroxide ion
C. H+ ion
D. HCN
E. H2O
- Messages
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- Reaction score
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farrukh said:
I'm not an A2 student, but I guess I may answer it. The answer has to be A(maybe). BUT according to the given conidtions, E may also be the answer.
- Messages
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- Reaction score
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farrukh said:
I guess ethanal. Again, phenols are in A2.
- Messages
- 772
- Reaction score
- 149
- Points
- 38
farrukh said:
Well, WOW! I didn't know that my AS concepts may solve A2 questions. :Yahoo!: Well, as far as I know, the rate determining step is the slowest step of the reaction. That is the step in which cyanide ions attack the carbonyl group carbon atom.